1. Field
The described technology generally relates to a rotary piston machine, especially a rotary engine.
2. Description of the Related Technology
In motor vehicles with an electric drive and a range extender, the internal combustion engine of the range extender is typically started and shut off while driving without any direct interaction by the driver, particularly in dependence on the state of charge of the battery of the electric drive. In contrast to motor vehicles that are driven by a mere internal combustion engine, the internal combustion engine of the range extender is not operated continuously in such motor vehicles, but rather only intermittently and typically has extended periods of inactivity.
When starting and shutting off the internal combustion engine of the range extender, it is important that the eccentric shaft and therefore the rotary piston have a defined rotational position in order to respectively achieve a reliable start and an advantageous stopping position. It may furthermore be desirable to measure the rotational speed and, if applicable, its fluctuations during the operation of the internal combustion engine.
For this purpose, the eccentric shaft is usually coupled to a shaft encoder, the circumferential region of which features a defined structure such as, for example, teeth and tooth spaces that can be detected by sensors during the rotation of the shaft encoder. This makes it possible to obtain information on the current rotational position and rotational speed of the shaft encoder or the shaft.